c7c71f7 · text · git.iko.soy

Simple implementation of isInfixOf

--HG-- extra : convert_revision : 88505a71433f083560ba6e7919751eff3dbe8b15

commitc7c71f7a5ca1c73b09dee0b544c64137db166982 authorBryan O'Sullivan <bos@serpentine.com> dateThu 12 Feb 2009, 07:47 (18 years ago) parent48685b2

2 files changed+10−1

unifiedsplit

Data/Text.hs+8−1

@@ -117,7 +117,7 @@ module Data.Text

117117 -- * Predicates

118118 , isPrefixOf

119119 , isSuffixOf

120− -- , isInfixOf

120+ , isInfixOf

121121

122122 -- * Searching

123123 , elem

@@ -861,5 +861,12 @@ isSuffixOf a@(Text _aarr _aoff alen) b@(Text barr boff blen) =

861861 | otherwise = Text barr (boff+d) alen

862862{-# INLINE isSuffixOf #-}

863863

864+-- | /O(n)/ The 'isInfixOf' function takes two 'Text's and returns

865+-- 'True' iff the first is contained, wholly and intact, anywhere

866+-- within the second.

867+isInfixOf :: Text -> Text -> Bool

868+isInfixOf needle haystack = L.any (isPrefixOf needle) (tails haystack)

869+{-# INLINE isInfixOf #-}

870+

864871errorEmptyList :: String -> a

865872errorEmptyList fun = error ("Data.Text." ++ fun ++ ": empty list")

tests/Properties.hs+2

@@ -143,6 +143,7 @@ prop_unwords = L.unwords `eq` (unpack . T.unwords . map pack)

143143prop_isPrefixOf s = L.isPrefixOf s`eqP` T.isPrefixOf (pack s)

144144prop_isPrefixOfS s = L.isPrefixOf s`eqP` (S.isPrefixOf (stream $ pack s) . stream)

145145prop_isSuffixOf s = L.isSuffixOf s`eqP` T.isSuffixOf (pack s)

146+prop_isInfixOf s = L.isInfixOf s `eqP` T.isInfixOf (pack s)

146147

147148prop_elem c = L.elem c `eqP` T.elem c

148149prop_filter p = L.filter p `eqP` (unpack . T.filter p)

@@ -242,6 +243,7 @@ tests = [

242243 ("prop_isPrefixOf", mytest prop_isPrefixOf),

243244 ("prop_isPrefixOfS", mytest prop_isPrefixOfS),

244245 ("prop_isSuffixOf", mytest prop_isSuffixOf),

246+ ("prop_isInfixOf", mytest prop_isInfixOf),

245247

246248 ("prop_elem", mytest prop_elem),

247249 ("prop_filter", mytest prop_filter),